At present, high blood uric acid is a direct or indirect risk factor of the diseases harmful to human health, such as gout, urinary calculi, renal disorder, obesity, hypertension, hyperlipemia, diabetic arteriosclerosis, cardiovascular disease, cerebrovascular disease and chronic nephritis. Urate is easy to deposit in endocardium, epicardium and cardiac valves, and further causing the abnormal phenomenon of cardiac damage, arrhythmia, cardiac insufficiency et al. It is found from the clinical observation of 6,403 patients that blood uric acid level is an independent risk factor for renal dysfunction (The Diagnosis and Treatment of Gout, written by Zhao Shengchuan in pages 40-47, published by Military Medical Science Press in February 2002). According to the statistics of International Health Organization, high blood uric acid sufferers live six years less on average than healthy people. According to 2015 Gout Classification Criteria: An American College of Rheumatology/European League Against Rheumatism Collaborative Initiative, the incidence of gout in the United States is 3.9%, in France is 0.9%, the United Kingdom 1.4%-2.5%, Germany 1.4%, New Zealand European and Maori 3.2% and 6.1 respectively. In China, the number of patients who die from the disease associated with high blood uric acid is up to more than three million each year, and the patients outnumber 500 million. To lower the level of high blood uric acid is the basis for the treatment of these diseases.
Uric acid is a heterocyclic compound containing carbon, hydrogen, nitrogen and oxygen, and a metabolite of purine. Its scientific name is 2,6,8-Trihydroxypurine, molecular formula is C5H4N4O3, molecular weight is 168.10, symbol is HUr, and its dissociation constants (PKa) are 5.75 (the 9th nitrogen dissociation) and 10.3 (the 3rd nitrogen dissociation) respectively. It is a white crystal. Its melting point >300° C. It is slightly soluble in boiling water and well soluble in alkali. The solubility with sodium urate solution at 37° C. is 8.0 mmol/L, and the solubility with uric acid at 37° C. is 0.5 mmol/L. Its solubility product constant Ksp is respectively as follows:Ksp(sodium urate)=(Na+) (Ur−)=0.008×0.008=6.4×10−5 Ksp(uric acid)=(H+) (Ur−)=0.0005×0.0005=2.5×10−7 
There is certain amount of uric acid contained in the body of healthy people. In addition, the body generates some new uric acid and discharges some uric acid for an amount equivalent to the generated amount every day in order to maintain balance. Once the balance is broken, the excess uric acid in vivo will lead to high blood uric acid, which is the main cause of gout. However, there are such a small number of gout patients that their determination of blood uric acid is normal when gout attacks just because of the precipitation of uric acid crystals. The case of elevated blood uric acid without gout attack is usually named as high blood uric acid.
At present, there are two major categories of drugs to lower blood uric acid and treat gout, that is, inhibit the synthesis of uric acid and accelerate the excretion of uric acid in vivo. Allopurinol Tablet is used to inhibit the synthesis of uric acid in vivo. The drugs used to promote urate excretion mainly include Sodium Bicarbonate, Colchicine, Probenecid, Anturane and Benzbromarone. However, no matter what medicine to use, corresponding side effects and contraindications will be generated. For example, colchicine can lower uric acid, but it will cause renal failure. Therefore, it is an urgent problem to be solved worldwide to develop safe, effective and quick blood uric acid lowering drugs.
The invention is originated from a patent applicant who had high blood uric acid and ultimately caused gout. In the physical examination in 1980, an excessive amount of blood uric acid was found from his body, but that did not attract his attention. The signs of gout appeared in 2006. Gout attacked him in 2008 and then he was unable to walk. Having been persistently exploring for eight years, no matter topical drugs or oral drugs, he tried all the drugs in person, and also allowed his gout wardmates who agreed to try the drugs to participate in the attempts. As the saying goes that he who repeatedly breaks arm eventually becomes an experienced doctor. Upon the practice of “repeatedly breaking arm”, the applicant finally found out the pharmaceutical use of KOH in lowering blood uric acid and treating gout.